The Great Deep
The Great Deep is a biome that spawns when a world is created. The ocean goes for miles now and goes very deep down. It is separated from the ocean by what appears to be a large doorway. It will ask the player for a Deep Sea Key, which will be dropped by any sea enemies with a 0.1% chance (0.2% in expert, 0.4% in master.) When the Deep Sea Key is used on the door, The Great Deep will be permenanetly unlocked for items and enemies. A lot of weapons are harvested from there too. It is split into a few layers. The Coral Zone This starts when the player unlocks the doorway and ends 60 blocks down. The easiest enemies spawn here. The water is only slightly darker than the ocean. Only Sharks and Squidlets spawn here. It can be accessed easily in Pre- Hard Mode. The Twilight Zone 60 blocks down, the water gets darker. Now the player can only see some light. Yellow Jellyfish and Green Jellyfish spawn here. The Spiky jellyfish variants also spawn here. When the player is at 130 blocks down this zone ends. Sharks also spawn here. Vampire Crabs may also spawn. The Midnight Zone At this point, almost everything is black. Nightmare Clams and Bloodthirst Clams spawn here. Brown Jellyfish also spawn here. Supermassive clams, Super sharks, and many hardmode enemies spawn here. Fishron do not spawn until the player is in the abyssal zone, which is just 210 blocks down. The Abyssal Zone Even darker than the midnight zone. The pressure of the ocean increases as now the player is miles below it. Fishron and most squid enemies in Hard Mode spawn here. The Magic Mirror is busted. This zone is recommended for Hard Mode only. The only way the player can escape is to climb back up to the Midnight Zone, and then unbust their mirror. Below the player, 300 blocks down, is the Hadal Zone. The Hadal Zone The final zone. The player will lose breathing extremely fast even with a gills potion. This is recommended for War Mode only. Many War Mode enemies spawn and the Void enemies will also spawn here. The player will need many accessories to make sure that they survive. However, down here, in Void chests that spawn at the bottom of the world, the player can find the Mirror Of Mind, an accessory that prevents Magic Mirrors from busting in the Abyssal Zone, and many other good War Mode accessories. Enemies (Pre - Hard Mode) Yellow Jellyfish Nightmare Clam (If the world has the Corruption) Bloodthirst Clam (If the world has the Crimson) Squidlet Spiky Blue Jellyfish (In Expert Mode Only) Spiky Pink Jellyfish (In Expert Mode Only) Spiky Yellow Jellyfish (In Expert Mode Only) Green Jellyfish Shark Vampire Crab Enemies (Hard Mode) Brown Jellyfish Void Jellyfish (Post moon-lord only) Supermassive Clam Super Shark Colossal Squid Vampire Squid Giant Squid Void Leviathan (Post-moon lord only) Bloodfeaster Crab Insanely Enraged Whale Fishron Enemies (War Mode) Spiked Void Jellyfish (Expert mode only) Void Shark Void Mimic Depth Mimic